The quick fix is to bypass the usb audio altogether and purchase a "3.5mm Stereo Jack to 2 x RCA" adaptor. You can get them for 61p inc delivery on Amazon
http://www.amazon.co.uk/WE11130-Adaptor-3-5mm-stereo-sockets/dp/B000L9C3GY/ref=sr_1_5?ie=UTF8&s=electronics&qid=1271193386&sr=8-5Take the 2 audio outs from your games console/vhs player and insert into the adaptor. Insert the adaptor into the "line In" input at the back of your pc on the sound card. This leaves just the yellow video lead going from the games console/vhs player into the ezcap.
Change the audio settings in your capture software from "usb audio device" to "line in"